Composite porous 3D foam for solar-driven atmospheric water harvesting in low humidity natural environment.

[Display omitted] • LiCl@CCP-PPy is simple and inexpensive to prepare, with fast water absorption–desorption capacity and cyclic stability. • LiCl@CCP-PPy is a hydrophilic macroporous material with a water absorption capacity of up to 2.86 g/g at 35 % RH and 25 °C. • LiCl@CCP-PPy has good storage capacity and ensures that the salt does not leak. • The water collection rate of LiCl@CCP-PPy in a single hygroscopic-desorption cycle in the Tengger Desert was 0.64 L/m2/d. Solar-driven atmospheric water harvesting (SAWH) has been recognized as a promising strategy to alleviate the freshwater crisis. Herein, we developed an efficient porous polymeric foam, LiCl@CCP-PPy, which has low preparation cost, strong adaptability and portability, and is very suitable for use as a wicking material in SAWH systems. LiCl@CCP-PPy contains abundant –NH 2 and –OH groups. These hydrophilic groups and excellent pore structure (porosity is 80.22 %) make it have a good moisture absorption effect even in low humidity environment. The moisture absorption capacity can reach 2.86 g/g at 35 % RH and 25 °C, and 4.48 g/g at 25 °C and 90 % RH. The saturated water absorption effect was 27.48 g/g. LiCl@CCP-PPy can be scaled up for production. In addition, LiCl@CCP-PPy has a high light absorption rate of more than 90 %, and the strong photothermal conversion ability of Polypyrene (PPy) enables the material to warm up rapidly under natural light, thereby accelerating the desorption process (96 % desorption rate at 1 kW/m2 for 3 h). Based on the above properties, LiCl@CCP-PPy was applied to the Tengger desert in northwest China. The final water production efficiency was 0.64 L/m2/d, and the collected water quality met the international drinking water standard. [ABSTRACT FROM AUTHOR]